This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The laboratory is currently exploring the Rgg-regulon. Rgg of S. pyogenes is a regulatory protein initially identified as being required for the expression of speB, which encodes a secreted cysteine protease (SPE B) that is likely to contribute to virulence. The SPE B protease degrades human extracellular matrix proteins and activates human enzymes such as matrix metalloproteases, which are involved in host tissue remodeling. In this manner, SPE B may contribute to the massive tissue destruction and concomitant dissemination of infection that is characteristic of necrotizing fasciitis and myositis, the so-called "flesh-eating" diseases. Interestingly, the tertiary structure of SPE B (but not the primary structure) resembles papain, the protease commercially sold as meat tenderizer. Dwight Luxon, disadvantaged high school student, worked with Dr. Chaussee during the summer of 2009 supported by $1650 in supplemental funds and the lab received $450 in support.